Light: Add hs null check to avoid crash

[cbrand]

Avoid a crash on the hs light check if none is set.

Fixes #746

[cbrand]

Checked in my home assistant installation with the L530 light bulbs and this null checks results that the lights are controllable again and do not show as unavailable.

[github-actions[bot]]

:tada: This PR is included in version 3.1.3 :tada:

The release is available on:

• 3.1.3
• GitHub release

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